pulsing dot

css only

by risto

HTML

<div id="dot"></div>

CSS

#dot {
    width: 16px;
    height: 16px;
    border: 1px solid rgb(214, 97, 107);
    background-color: rgba(214, 97, 107, 0.5);
    border-radius: 100%;
    animation: pulsate 1.5s ease-out;
    animation-iteration-count: infinite;
    opacity: 0.5;
}
@keyframes pulsate {
    0% {
        opacity: 0.5;
    }
    50% {
        opacity: 1.0;
    }
    100% {
        opacity: 0.5;
    }
}